A study in generation and detection of amplitude-modulated signals using sine-wave crossings technique

Abstract

A simple circuit for generating amplitude-modulated signals (conventional AM and double side band (DSB) using sine-wave crossings (SWC) technique is reported. It can be considered as a modification to Piwnicki's circuit and has the feature that it uses a single oscillator instead of a quadrature one and hence can be employed in applications where carrier frequency is not fixed. A suggestion for transmitting AM and DSB signals (in binary form) using SWC technique is proposed where coherent detection can be achieved easily in the receiver. Good correlation is observed between practical and theoretical results.